BOSTON -- Derek Jeter caught a flight to Kansas City for the All-Star Game. But before he did, the Yankees captain endured an eventful evening. During last night's 7-3 win over the Red Sox, Jeter felt what called a "muscle spasm" in his right shoulder.

Then, he did the unthinkable, dropping Cody Ross' routine pop-up.

"If you think about it, it's probably the most embarrassing thing that could happen to a player on defense," said Jeter, whose error led to a Red Sox run.

Jeter could laugh at the miscue because the Yankees went on to win. Still, he wished he had a better explanation for the rare mistake. There was no wind on the play. He used both hands, though as he pointed out, the ball found neither of them.

"I wish I had a good story for you and say a bird hit it or something," Jeter said. "But it basically was a pop up and I dropped it."

He only remembers flubbing a pop up just once in a game against the Angels in 2009.

The error surprised Joe Girardi.

"I've seen it happen twice and both of them were under my managerial watch, so it must be me," he said. "I'll tell you, he's as good at pop-ups as I've ever seen."

As for Jeter's muscle spasms, he insisted "it's really not a big deal." He admitted later on that the spasms began shortly after dropping the Ross' infield fly.